Which opioid is only available in generic form?

Codeine is exclusively available in generic form due to its common use and the extended duration of its patents, which have long since expired. The lack of any brand-name version on the market allows for cost-effective access, making it widely available for prescriptions. This status is attributed to its historical presence, as it has been used for many years in various formulations for pain relief and cough suppression. Hydrocodone, fentanyl, and morphine all have brand-name formulations available, as well as their generic counterparts, which distinguishes codeine's unique availability situation.